The K4000/K4000s LED Lights can be powered by V-mount battery, 3.5mm DC input, or by a more robust V-mount to AC wall adapter. The filters are offset to eliminate multi-shadow effects typically found on panels that use multi-led bulb arrays. Sold separately these lights run up to $500/each, but as a 3 piece kit (which includes a travel case) these lights end up running as low as $330/each (found here). If you want to get a few more ideas on how professionals are using these lights, take a look at the F&V Video Gallery page (found here).